Code |
c
c###################################################################
c
subroutine jborn2(pe, pcf, kncf, pfit, kermsg)
c
c this is a subroutine to calculate cross sections (cm[2])
c versus energy (ev) using a formula based on a semiempirical
c modification of the bethe-born formula.
c (this expression is identical to that used in jborn1, however,
c to be able to uniquely identify the different choices of
c weighting seperate routines have been kept, see
c doc=h-he-plasma)
c
c pcf is the coefficient data array, where
c
c pcf(1) = the threshold energy for the reaction (ev)
c
c pcf(2) = the minimum energy for the application of the
c semiempirical formulae.
c
c pcf(3) = coefficient a
c
c pcf(4) = coefficient n
c
c pe = collision energy in ev
c
c kermsg = blank if no errors
c
c pfit = cross section in cm[2]
c
c written by j. j. smith , iaea atomic and molecular data unit
c
c------------------------------------------------------------------------
c
double precision pe, pcf, pfit
dimension pcf(11)
character*(*) kermsg
eth=pcf(1)
emin = pcf(2)
a=pcf(3)
n=pcf(4)
an=n
if(pe .ge. eth) then
kermsg = ' '
else
kermsg = 'energy is below threshold for reaction in jborn2'
return
endif
c
pfit = a*((eth/pe)**an) *dlog(pe/eth)
100 return
c
end |